The present invention relates to the production of endodontic instruments for preparing dental canals, and more particularly, to a type of canal instrument which is known as a “dental reamer” and which has a working cross-section, called a “blade”, which comprises three flutes forming three cutting lips.
Canal instruments which have a working cross-section comprised of three flutes forming three cutting lips are known in the art. In particular, this type of instrument is known from prior French Patent Applications No. 96 04987 and No. 96 14347.
The instruments described in these Patent Applications have a circular symmetry, on the order of three or more, depending on the number of cutting lips of the instrument. As a result, when the instrument is used (rotated) in a curved dental canal, the instrument follows the axis of the canal by virtue of the equilibrium of the forces applied to the instrument.
This type of instrument is satisfactory, except when the canal cannot be assimilated to a hole having a circular cross-section. This is because, in this latter case, the forces applied during preparation of the canal are no longer in equilibrium, and there is a risk that the trajectory of the instrument will deviate from the axis of the dental canal. This deviation can have very serious consequences since it can lead to the formation of an incorrect path, or even a perforation of the canal.